Portable communication devices (e.g., smart phones and smart watches) are becoming increasingly waterproof by implementing electronic components inside sealed enclosures. However, certain components such as environmental (e.g., pressure, temperature and humidity) sensors, gas sensors, particulate matter (PM) sensors, speakers and microphones rely on physical interaction with the external environment for proper functionality. The physical interaction can be through a small opening provided on the enclosure. Exposure to the environmental aggressors such as fresh and salt water, skin oil, dust, sunscreens can cause a variety of system integration problems.
Port occlusion by water or debris is among the problems, which can result in degradation in user experience, poor device reliability and/or device misreading. As an example, the accuracy of pressure sensors, when detecting external pressure changes, can be greatly reduced if residual water occludes the sensor surface resulting in misreading. As the water evaporates (which can take hours), false pressure-change signals can be detected. For example, when pressure is sensed for measuring height to count the number of stairs climbed by a user, the false pressure-change signals can indicate false or missed flight of stairs, which degrades the user experience. The existing gel-based sensors (e.g., pressure sensors), although may work for their intended applications, but may have a number of shortcomings. For example, the sensor temperature coefficient offset (TCO) may change from the time of testing to the time of integration into a system and continue to drift during the product lifetime. Further, strain induced effects are not addressed in the existing solutions.